STMicroelectronics EVL6566B-65W

Overview

EVL6566B-65W from STMicroelectronics is a 65 W, 12 V/5.42 A universal-input (90–264 V_AC) flyback AC-DC adapter evaluation board built around the L6566B current-mode PWM controller and TSM1014 CC/CV feedback IC. It delivers 83.9% efficiency at 230 V_AC, <200 mW no-load input power, and meets EN61000-3-2 Class-D harmonics and EN55022 Class-B EMI standards for consumer and home appliance power supplies.

For engineers reviewing the EVL6566B-65W datasheet, EVL6566B-65W application, EVL6566B-65W test results, or EVL6566B-65W bill of materials, this reference design provides validated performance data, burst-mode standby operation, open-loop and over-current protection waveforms, and full schematics for rapid implementation of energy-efficient low-power AC-DC adapters.

Technical Context

The EVL6566B-65W implements a fixed-frequency (79–80 kHz) flyback converter operating in both continuous and discontinuous conduction modes. Its control loop uses primary-side sensing via the L6566B's ZCD pin for OVP and CS pin for peak current limiting, with secondary-side regulation via optocoupler-coupled error amplifier (TSM1014).

Burst-mode operation at no load reduces standby consumption to 66 mW at 90 V_AC and 200 mW at 265 V_AC. Protection features include latch-off OVP triggered by auxiliary winding voltage, hiccup-mode OCP with V_CC UVLO recovery, and brownout disable via AC_OK pin (threshold 0.45 V).

Key Specifications

Availability

EVL6566B-65W is available at Aetrix Electronics and suitable for consumer power adapters, smart home appliance SMPS, and industrial auxiliary supplies requiring stable component supply, fast prototyping validation, and regulatory-compliant reference designs.

Supply support for EVL6566B-65W includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, specializing in power management, analog, microcontrollers, and automotive ICs with vertical manufacturing and broad distribution.

The EVL6566B-65W belongs to ST's AC-DC evaluation board portfolio, developed to accelerate adoption of its high-efficiency PWM controllers (e.g., L6566B) in cost-sensitive, space-constrained offline power supplies.

FAQ

What is the purpose of the TSM1014 on this board?

The TSM1014 is a low-power CC/CV controller in MiniSO-8 package that implements precise secondary-side voltage and current regulation. It integrates a 2.5 V reference and error amplifier to drive the SFH617A-4 optocoupler, enabling tight output regulation (<±3%) across line and load while supporting constant-current charging profiles.

How does the L6566B enable ultra-low standby consumption?

The L6566B integrates a high-voltage current source that charges the V_CC capacitor (C2/C3) directly from the rectified DC bus during startup. Once V_CC reaches ~12.5 V, the HV source shuts off, eliminating continuous dissipation. During no-load, it enters burst mode-switching only intermittently-to maintain regulation while drawing <200 mW from the AC line.

Can this board be modified for 5 V / 10 A output?

No-this board is fixed at 12 V / 5.42 A due to transformer turns ratio (10–11:6–2 = 12 V secondary), output rectifier rating (STPS20H100FP), and feedback resistor network (R17 = 23.4 kΩ). Changing output voltage requires rewinding the transformer, replacing Q201, and recalibrating the TSM1014 feedback divider and OVP threshold.

Does the board include input inrush current limiting?

Yes-the design incorporates a 10 Ω NTC thermistor (TH1) in series with the AC input to limit cold-start inrush current into bulk capacitors C4 and C5. This prevents fuse blowing and contact welding in repeated plug-in cycles, complying with IEC 61000-4-11 surge immunity requirements.